The present invention relates to a method of producing products from polymer materials having a medicamentous depot effect for use in the medical field in or on the human organism.
The preparation of products from polymer materials for medical uses with the aid of conventional curing methods, namely by hot-air, steam or UHF methods or by LCM methods (liquid curing methods), is already known. Polymer products having a medicamentous depot effect cannot be produced with the aid of these methods because of a great thermal load.
Furthermore, patent specification DE 37 41 342 discloses a method for producing a medicinal material with a high antithrombogenicity, which material is inter alia suited for catheters and other medicinal instruments that come into contact with tissues and flowing blood. The described material can be produced by polymerization of a methacrylamide derivative with a tertiary amino group or a hydrophilic monomer with a copolymerization-accelerating characteristic on a high-molecular polyolefin or polyurethane substrate. Active spots are produced on the substrate through ionizing radiation. The active substrate is subsequently immersed into a solution of a monomer. The antithrombogenic effect of the material is consequently due to the grafted monomer.
As becomes apparent from the above, the material with the antithrombogenic effect can only be fixed to the substrate superficially in the known prior art. As a consequence, it is not possible to ensure a long-lasting and continuous release of the biologically active substance that would be controllable via concentration drop. Furthermore, this publication does not hint at any biological activity of the finished products.
Furthermore, DD 275697 discloses a method of producing tubes for medicinal uses that contain biologically active polymer materials. .beta.-rays are used for curing, and metal oxides, such as ZnO or TiO.sub.2 as curing activators. Although this method avoids extremely high temperature loads as are caused by conventional methods, there are other disadvantages. For instance, relatively high radiation doses which, in turn, produce a considerable amount of reaction heat are required for curing. To eliminate the reaction heat, the tubes must therefore be pulled over steel mandrels prior to curing and, after confection and packaging, they must be subjected to a separate sterilization process which, on the one hand, increases the production costs and, on the other hand, jeopardizes the continuance of the biological activity beyond the production process, for it is known that high heat and/or radiation loads impair the biological activity of organic compounds. Moreover, the metal oxides ZnO and TiO.sub.2 that are used as activators must be classified as toxic and therefore as detrimental to the body.
It is therefore the object of the present invention to provide a method of producing products from polymer materials having a medicamentous depot effect, the method overcoming the drawbacks of the known prior art and being adapted to be carried out at low costs.